Studies done by this project identified the sex pheromone of Dermacentor variabilis (Say) and Dermacentor andersoni Stiles, namely, 2,6-dichlorophenol. The foveal glands were found to be the sex pheromone glands, with the pheromone released via the pores of the foveae dorsales. Partially fed D. andersoni females were found to produce approximately 22 nanograms of sex pheromone per tick per day. The occurrence of other halogenated compounds suspected to occur in tick extracts is being investigated by GLC. Other studies will investigate the mechanics of transport and release of the sex pheromone, ultrastructure and function of the foveal glands, and, finally, the genetic basis of inheritance, if any, of differences in sex attractant potential within the tick population. Exploratory investigations on practical applications of sex pheromone research are being done using PVC collars and dusts to disrupt mate finding behavior in ticks.